Using Fura-2AM microfluorimetry we have shown for the first time that sigma-1 receptor agonist – tricyclic antidepressant amitriptyline - significantly inhibits glutoxim- and molixan-induced Ca2+ responses in rat peritoneal macrophages. The results suggest possible involvement of sigma-1 receptors in signaling cascade induced by glutoxim or molixan and leading to intracellular Ca2+ concentration increase in macrophages.